How to setup two foreign keys to the same parent column (Entity Framework)

Question

I'm using ASP.NET MVC and I have the following class models

Position:

public enum PosType
{
    ICC, FP
}

public class Position
{
    public int Id { get; set; }
    public string Name { get; set; }
    public PosType? PosType { get; set; }
}

Staff:

public class Staff
{
    public int Id { get; set; }
    public string StaffName { get; set; }

    //FK to Position
    public int PositionId { get; set; }

    //Navigation property
    public virtual Position Position { get; set; }

Member:

public class Member
{
    public int Id { get; set; }
    public string MemberName { get; set; }

    //FK to Staff model which stores the ICC Staff Type value
    public int? StaffId { get; set; }

    //FK to Staff model which stores the FP Staff Type value
    public int? FPNumber { get; set; }

    //Navigation property 
    public virtual Staff Staff { get; set; }

On the Member model the StaffId property is a foreign key to the Staff model which is a pretty straight forward approach. The issue I'm having is how to handle the FPnumber property since I would like it to be a foreign key to the Staff model as well. My overall goal is have the Member.StaffId property store ICC staff type and the Member.FPNumber property store FP staff type. I tried adding the ForeignKey attribute to the FPNumber property, but it did not work since the StaffIdgot removed from the Member table. Any other suggestions?

Possible duplicate of [Mapping a foreign key with a custom column name](https://stackoverflow.com/questions/11148662/mapping-a-foreign-key-with-a-custom-column-name) — Tipx, Aug 15 '18 at 21:17

3dd · Answer 1 · 2018-08-15T21:22:00.317

2

This should do the trick

public class Member
{
public int Id { get; set; }
public string MemberName { get; set; }

//FK to Staff model which stores the ICC Staff Type value
[ForeignKey("Staff")]
public int? StaffId { get; set; }

//FK to Staff model which stores the FP Staff Type value
[ForeignKey("FPStaff")]
public int? FPNumber { get; set; }

//Navigation property 
public virtual Staff Staff { get; set; }  //Use a better descriptive Name than Staff

public virtual Staff FPStaff{ get; set; }
}

edited Aug 15 '18 at 21:22

answered Aug 15 '18 at 21:18

3dd

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2

I would also recommend renaming the "Staff" member to be more precise. – Tipx Aug 15 '18 at 21:20

How to setup two foreign keys to the same parent column (Entity Framework)

1 Answers1